Merge branch 'master' of https://github.com/Maiklins/tutorials into JAVA-7244-Review_log_statements_for_projects

 Conflicts:

	algorithms-searching/src/test/java/com/baeldung/algorithms/quadtree/QuadTreeSearchUnitTest.java

persistence-modules/apache-derby/pom.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>persistence-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>apache-derby</artifactId>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/org.apache.derby/derby -->
+        <dependency>
+            <groupId>org.apache.derby</groupId>
+            <artifactId>derby</artifactId>
+            <version>10.13.1.1</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.derby/derbyclient -->
+        <dependency>
+            <groupId>org.apache.derby</groupId>
+            <artifactId>derbyclient</artifactId>
+            <version>10.13.1.1</version>
+        </dependency>
+
+    </dependencies>
+
+
+</project>

persistence-modules/apache-derby/src/main/java/com/baeldung/derby/DerbyApplicationDemo.java

@@ -0,0 +1,39 @@
+package com.baeldung.derby;
+
+import java.sql.*;
+
+/**
+ * Created by arash on 14.10.21.
+ */
+
+public class DerbyApplicationDemo {
+    public static void main(String[] args) {
+        runner("jdbc:derby:baeldung;create=true");
+    }
+
+    private static void runner(String urlConnection) {
+        try {
+            Connection con = DriverManager.getConnection(urlConnection);
+            Statement statement = con.createStatement();
+            if (!isTableExists("authors", con)) {
+                String createSQL = "CREATE TABLE authors (id INT PRIMARY KEY,first_name VARCHAR(255),last_name VARCHAR(255))";
+                statement.execute(createSQL);
+                String insertSQL = "INSERT INTO authors VALUES (1, 'arash','ariani')";
+                statement.execute(insertSQL);
+            }
+            String selectSQL = "SELECT * FROM authors";
+            ResultSet result = statement.executeQuery(selectSQL);
+            while (result.next()) {
+                // use result here
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static boolean isTableExists(String tableName, Connection connection) throws SQLException {
+        DatabaseMetaData meta = connection.getMetaData();
+        ResultSet result = meta.getTables(null, null, tableName.toUpperCase(), null);
+        return result.next();
+    }
+}

persistence-modules/deltaspike/pom.xml

@@ -16,6 +16,46 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <dependencyManagement>
+        <dependencies>
+            <!-- for junit5 to successfully be able to discover junit4 tests, we need 4.12+ version of junit:junit in the classpath. hence forcing the
+            latest 4.13.2 available version for junit5 compatibility -->
+            <dependency>
+                <groupId>junit</groupId>
+                <artifactId>junit</artifactId>
+                <version>${junit.version}</version>
+                <scope>test</scope>
+            </dependency>
+            <!-- JBoss distributes a complete set of Java EE 7 APIs including a Bill of Materials (BOM). 
+                A BOM specifies the versions of a "stack" (or a collection) of artifacts. We use this here so that we 
+                always get the correct versions of artifacts. Here we use the jboss-javaee-7.0-with-tools stack (you 
+                can read this as the JBoss stack of the Java EE 7 APIs, with some extras tools for your project, such 
+                as Arquillian for testing) and the jboss-javaee-7.0-with-hibernate stack you can read this as the JBoss 
+                stack of the Java EE 7 APIs, with extras from the Hibernate family of projects) -->
+            <dependency>
+                <groupId>org.wildfly.bom</groupId>
+                <artifactId>jboss-javaee-7.0-with-tools</artifactId>
+                <version>${jboss.bom.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+            <dependency>
+                <groupId>org.wildfly.bom</groupId>
+                <artifactId>jboss-javaee-7.0-with-hibernate</artifactId>
+                <version>${jboss.bom.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.deltaspike.distribution</groupId>
+                <artifactId>distributions-bom</artifactId>
+                <version>${deltaspike.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <dependencies>
         <!-- First declare the APIs we depend on and need for compilation. All of them are provided by 
             JBoss WildFly -->
@@ -245,38 +285,6 @@
         </repository>
     </repositories>
 
-    <dependencyManagement>
-        <dependencies>
-            <!-- JBoss distributes a complete set of Java EE 7 APIs including a Bill of Materials (BOM). 
-                A BOM specifies the versions of a "stack" (or a collection) of artifacts. We use this here so that we 
-                always get the correct versions of artifacts. Here we use the jboss-javaee-7.0-with-tools stack (you 
-                can read this as the JBoss stack of the Java EE 7 APIs, with some extras tools for your project, such 
-                as Arquillian for testing) and the jboss-javaee-7.0-with-hibernate stack you can read this as the JBoss 
-                stack of the Java EE 7 APIs, with extras from the Hibernate family of projects) -->
-            <dependency>
-                <groupId>org.wildfly.bom</groupId>
-                <artifactId>jboss-javaee-7.0-with-tools</artifactId>
-                <version>${jboss.bom.version}</version>
-                <type>pom</type>
-                <scope>import</scope>
-            </dependency>
-            <dependency>
-                <groupId>org.wildfly.bom</groupId>
-                <artifactId>jboss-javaee-7.0-with-hibernate</artifactId>
-                <version>${jboss.bom.version}</version>
-                <type>pom</type>
-                <scope>import</scope>
-            </dependency>
-            <dependency>
-                <groupId>org.apache.deltaspike.distribution</groupId>
-                <artifactId>distributions-bom</artifactId>
-                <version>${deltaspike.version}</version>
-                <type>pom</type>
-                <scope>import</scope>
-            </dependency>
-        </dependencies>
-    </dependencyManagement>
-
     <properties>
         <querydsl.version>3.7.4</querydsl.version>
         <deltaspike.version>1.8.2</deltaspike.version>

persistence-modules/flyway/pom.xml

@@ -64,8 +64,8 @@
     </build>
 
     <properties>
-        <flyway-core.version>5.2.3</flyway-core.version>
-        <flyway-maven-plugin.version>5.0.2</flyway-maven-plugin.version>
+        <flyway-core.version>8.0.0</flyway-core.version>
+        <flyway-maven-plugin.version>8.0.0</flyway-maven-plugin.version>
     </properties>
 
 </project>

persistence-modules/flyway/src/main/java/com/baeldung/flywaycallbacks/ExampleFlywayCallback.java

@@ -1,33 +1,40 @@
 package com.baeldung.flywaycallbacks;
 
-import java.sql.Connection;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.flywaydb.core.api.MigrationInfo;
-import org.flywaydb.core.api.callback.BaseFlywayCallback;
+import org.flywaydb.core.api.callback.Callback;
+import org.flywaydb.core.api.callback.Context;
+import org.flywaydb.core.api.callback.Event;
 
-public class ExampleFlywayCallback extends BaseFlywayCallback {
+public class ExampleFlywayCallback implements Callback {
 
-    private Log log = LogFactory.getLog(getClass());
+    private final Log log = LogFactory.getLog(getClass());
 
     @Override
-    public void afterEachMigrate(Connection connection, MigrationInfo info) {
-        log.info("> afterEachMigrate");
+    public boolean supports(Event event, Context context) {
+        return event == Event.AFTER_EACH_MIGRATE || event == Event.AFTER_MIGRATE || event == Event.BEFORE_EACH_MIGRATE || event == Event.BEFORE_MIGRATE;
     }
 
     @Override
-    public void afterMigrate(Connection connection) {
-        log.info("> afterMigrate");
+    public boolean canHandleInTransaction(Event event, Context context) {
+        return true;
     }
 
     @Override
-    public void beforeEachMigrate(Connection connection, MigrationInfo info) {
-        log.info("> beforeEachMigrate");
+    public void handle(Event event, Context context) {
+        if (event == Event.AFTER_EACH_MIGRATE) {
+            log.info("> afterEachMigrate");
+        } else if (event == Event.AFTER_MIGRATE) {
+            log.info("> afterMigrate");
+        } else if (event == Event.BEFORE_EACH_MIGRATE) {
+            log.info("> beforeEachMigrate");
+        } else if (event == Event.BEFORE_MIGRATE) {
+            log.info("> beforeMigrate");
+        }
     }
 
     @Override
-    public void beforeMigrate(Connection connection) {
-        log.info("> beforeMigrate");
+    public String getCallbackName() {
+        return ExampleFlywayCallback.class.getSimpleName();
     }
 }

persistence-modules/flyway/src/test/java/com/baeldung/flywaycallbacks/FlywayApplicationUnitTest.java

@@ -18,7 +18,7 @@ import org.springframework.test.context.junit4.SpringRunner;
 @ContextConfiguration(classes = FlywayCallbackTestConfig.class)
 public class FlywayApplicationUnitTest {
 
-    private Log log = LogFactory.getLog(getClass());
+    private final Log log = LogFactory.getLog(getClass());
 
     @Autowired
     private DataSource dataSource;
@@ -26,43 +26,47 @@ public class FlywayApplicationUnitTest {
     @Test
     public void migrateWithNoCallbacks() {
         logTestBoundary("migrateWithNoCallbacks");
-        Flyway flyway = new Flyway();
-        flyway.setDataSource(dataSource);
-        flyway.setLocations("db/migration");
-        flyway.migrate(); 
+        Flyway flyway = Flyway.configure()
+                .dataSource(dataSource)
+                .locations("db/migration")
+                .load();
+        flyway.migrate();
     }
 
     @Test
     public void migrateWithJavaCallbacks() {
         logTestBoundary("migrateWithJavaCallbacks");
-        Flyway flyway = new Flyway();
-        flyway.setDataSource(dataSource);
-        flyway.setLocations("db/migration");
-        flyway.setCallbacks(new ExampleFlywayCallback());
+        Flyway flyway = Flyway.configure()
+                .dataSource(dataSource)
+                .locations("db/migration")
+                .callbacks(new ExampleFlywayCallback())
+                .load();
         flyway.migrate();
     }
 
     @Test
     public void migrateWithSqlCallbacks() {
         logTestBoundary("migrateWithSqlCallbacks");
-        Flyway flyway = new Flyway();
-        flyway.setDataSource(dataSource);
-        flyway.setLocations("db/migration", "db/callbacks");
-        flyway.migrate(); 
+        Flyway flyway = Flyway.configure()
+                .dataSource(dataSource)
+                .locations("db/migration", "db/callbacks")
+                .load();
+        flyway.migrate();
     }
 
     @Test
     public void migrateWithSqlAndJavaCallbacks() {
         logTestBoundary("migrateWithSqlAndJavaCallbacks");
-        Flyway flyway = new Flyway();
-        flyway.setDataSource(dataSource);
-        flyway.setLocations("db/migration", "db/callbacks");
-        flyway.setCallbacks(new ExampleFlywayCallback());
-        flyway.migrate(); 
+        Flyway flyway = Flyway.configure()
+                .dataSource(dataSource)
+                .locations("db/migration", "db/callbacks")
+                .callbacks(new ExampleFlywayCallback())
+                .load();
+        flyway.migrate();
     }
 
     private void logTestBoundary(String testName) {
         System.out.println("\n");
         log.info("> " + testName);
     }
- }
+}

persistence-modules/hibernate-enterprise/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
-<project
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
-    xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>hibernate-enterprise</artifactId>
     <version>0.0.1-SNAPSHOT</version>

persistence-modules/hibernate-exceptions/README.md

@@ -2,4 +2,5 @@
 
 - [Hibernate could not initialize proxy – no Session](https://www.baeldung.com/hibernate-initialize-proxy-exception)
 - [Hibernate Error “No Persistence Provider for EntityManager”](https://www.baeldung.com/hibernate-no-persistence-provider)
-- [TransactionRequiredException Error](https://www.baeldung.com/jpa-transaction-required-exception)
+- [TransactionRequiredException Error](https://www.baeldung.com/jpa-transaction-required-exception)
+- [Hibernate’s “Object References an Unsaved Transient Instance” Error](https://www.baeldung.com/hibernate-unsaved-transient-instance-error)

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/HibernateUtil.java

@@ -0,0 +1,51 @@
+package com.baeldung.hibernate.exception.transientobject;
+
+import java.util.Properties;
+
+import com.baeldung.hibernate.exception.transientobject.entity.Address;
+import com.baeldung.hibernate.exception.transientobject.entity.Department;
+import com.baeldung.hibernate.exception.transientobject.entity.Author;
+import com.baeldung.hibernate.exception.transientobject.entity.Book;
+import com.baeldung.hibernate.exception.transientobject.entity.Employee;
+import com.baeldung.hibernate.exception.transientobject.entity.User;
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.cfg.Environment;
+import org.hibernate.service.ServiceRegistry;
+
+public class HibernateUtil {
+    private static SessionFactory sessionFactory;
+
+    public static SessionFactory getSessionFactory() {
+        if (sessionFactory == null) {
+            try {
+                Configuration configuration = new Configuration();
+                Properties settings = new Properties();
+                settings.put(Environment.DRIVER, "org.hsqldb.jdbcDriver");
+                settings.put(Environment.URL, "jdbc:hsqldb:mem:transient");
+                settings.put(Environment.USER, "sa");
+                settings.put(Environment.PASS, "");
+                settings.put(Environment.DIALECT, "org.hibernate.dialect.HSQLDialect");
+                settings.put(Environment.SHOW_SQL, "true");
+                settings.put(Environment.USE_SQL_COMMENTS, "true");
+                settings.put(Environment.HBM2DDL_AUTO, "update");
+                configuration.setProperties(settings);
+                configuration.addAnnotatedClass(User.class);
+                configuration.addAnnotatedClass(Address.class);
+                configuration.addAnnotatedClass(Department.class);
+                configuration.addAnnotatedClass(Employee.class);
+                configuration.addAnnotatedClass(Book.class);
+                configuration.addAnnotatedClass(Author.class);
+
+
+                ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
+                        .applySettings(configuration.getProperties()).build();
+                sessionFactory = configuration.buildSessionFactory(serviceRegistry);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return sessionFactory;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/Address.java

@@ -0,0 +1,74 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "address")
+public class Address {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private Long id;
+
+    @Column(name = "city")
+    private String city;
+
+    @Column(name = "street")
+    private String street;
+
+    @OneToOne(mappedBy = "address")
+    private User user;
+
+    public Address() {
+    }
+
+    public Address(String city, String street) {
+        this.city = city;
+        this.street = street;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public void setCity(String city) {
+        this.city = city;
+    }
+
+    public String getStreet() {
+        return street;
+    }
+
+    public void setStreet(String street) {
+        this.street = street;
+    }
+
+    public User getUser() {
+        return user;
+    }
+
+    public void setUser(User user) {
+        this.user = user;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/Author.java

@@ -0,0 +1,71 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+import org.hibernate.annotations.Cascade;
+import org.hibernate.annotations.CascadeType;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+import java.util.HashSet;
+import java.util.Set;
+
+@Entity
+@Table(name = "author")
+public class Author {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private int id;
+
+    @Column(name = "name")
+    private String name;
+
+    @ManyToMany
+    @Cascade({ CascadeType.SAVE_UPDATE, CascadeType.MERGE, CascadeType.PERSIST})
+    @JoinColumn(name = "book_id")
+    private Set<Book> books = new HashSet<>();
+
+    public void addBook(Book book) {
+        books.add(book);
+    }
+
+    // standard getters and setters
+
+    public Author() {
+    }
+
+    public Author(String name) {
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Set<Book> getBooks() {
+        return books;
+    }
+
+    public void setBooks(Set<Book> books) {
+        this.books = books;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/Book.java

@@ -0,0 +1,72 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+
+import org.hibernate.annotations.Cascade;
+import org.hibernate.annotations.CascadeType;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToMany;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import java.util.HashSet;
+import java.util.Set;
+
+@Entity
+@Table(name = "book")
+public class Book {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private int id;
+
+    @Column(name = "title")
+    private String title;
+
+    @ManyToMany
+    @Cascade({ CascadeType.SAVE_UPDATE, CascadeType.MERGE, CascadeType.PERSIST})
+    @JoinColumn(name = "author_id")
+    private Set<Author> authors = new HashSet<>();
+
+    public void addAuthor(Author author) {
+        authors.add(author);
+    }
+
+    // standard getters and setters
+
+    public Book() {
+    }
+
+    public Book(String title) {
+        this.title = title;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public Set<Author> getAuthors() {
+        return authors;
+    }
+
+    public void setAuthors(Set<Author> authors) {
+        this.authors = authors;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/Department.java

@@ -0,0 +1,70 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import java.util.HashSet;
+import java.util.Set;
+
+@Entity
+@Table(name = "department")
+public class Department {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private int id;
+
+    @Column(name = "name")
+    private String name;
+
+    @OneToMany(mappedBy = "department", cascade = CascadeType.ALL, orphanRemoval = true)
+    private Set<Employee> employees = new HashSet<>();
+
+    public void addEmployee(Employee employee) {
+        employees.add(employee);
+    }
+
+    // standard getters and setters
+
+    public Department() {
+    }
+
+    public Department(int id) {
+        this.id = id;
+    }
+
+    public Department(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Set<Employee> getEmployees() {
+        return employees;
+    }
+
+    public void setEmployees(Set<Employee> employees) {
+        this.employees = employees;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/Employee.java

@@ -0,0 +1,66 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+
+import org.hibernate.annotations.Cascade;
+import org.hibernate.annotations.CascadeType;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "employee")
+public class Employee {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private int id;
+
+    @Column(name = "name")
+    private String name;
+
+    @ManyToOne
+    @Cascade(CascadeType.SAVE_UPDATE)
+    @JoinColumn(name = "department_id")
+    private Department department;
+
+    // standard getters and setters
+
+    public Employee() {
+    }
+
+    public Employee(String name) {
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}

persistence-modules/hibernate-exceptions/src/main/java/com/baeldung/hibernate/exception/transientobject/entity/User.java

@@ -0,0 +1,76 @@
+package com.baeldung.hibernate.exception.transientobject.entity;
+
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "user")
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    private int id;
+
+    @Column(name = "first_name")
+    private String firstName;
+
+    @Column(name = "last_name")
+    private String lastName;
+
+    @OneToOne(cascade = CascadeType.ALL)
+    @JoinColumn(name = "address_id", referencedColumnName = "id")
+    private Address address;
+
+    public User() {
+    }
+
+    public User(String firstName, String lastName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(Address address) {
+        this.address = address;
+    }
+}

persistence-modules/hibernate-exceptions/src/test/java/com/baeldung/hibernate/exception/transientobject/HibernateTransientObjectUnitTest.java

@@ -0,0 +1,84 @@
+package com.baeldung.hibernate.exception.transientobject;
+
+import com.baeldung.hibernate.exception.transientobject.entity.Address;
+import com.baeldung.hibernate.exception.transientobject.entity.Department;
+import com.baeldung.hibernate.exception.transientobject.entity.Author;
+import com.baeldung.hibernate.exception.transientobject.entity.Book;
+import com.baeldung.hibernate.exception.transientobject.entity.Employee;
+import com.baeldung.hibernate.exception.transientobject.entity.User;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class HibernateTransientObjectUnitTest {
+
+    private static SessionFactory sessionFactory;
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @BeforeClass
+    public static void init() {
+        sessionFactory = HibernateUtil.getSessionFactory();
+    }
+
+    @Test
+    public void whenSaveEntitiesWithOneToOneAssociation_thenSuccess() {
+        User user = new User("Bob", "Smith");
+        Address address = new Address("London", "221b Baker Street");
+        user.setAddress(address);
+        Session session = sessionFactory.openSession();
+        session.beginTransaction();
+        session.save(user);
+        session.getTransaction().commit();
+        session.close();
+    }
+
+    @Test
+    public void whenSaveEntitiesWithOneToManyAssociation_thenSuccess() {
+        Department department = new Department();
+        department.setName("IT Support");
+        Employee employee = new Employee("John Doe");
+        employee.setDepartment(department);
+        Session session = sessionFactory.openSession();
+        session.beginTransaction();
+        session.save(employee);
+        session.getTransaction().commit();
+        session.close();
+    }
+
+    @Test
+    public void whenSaveEntitiesWithManyToManyAssociation_thenSuccess_1() {
+        Book book = new Book("Design Patterns: Elements of Reusable Object-Oriented Software");
+        book.addAuthor(new Author("Erich Gamma"));
+        book.addAuthor(new Author("John Vlissides"));
+        book.addAuthor(new Author("Richard Helm"));
+        book.addAuthor(new Author("Ralph Johnson"));
+        Session session = sessionFactory.openSession();
+        session.beginTransaction();
+        session.save(book);
+        session.getTransaction().commit();
+        session.close();
+    }
+
+    @Test
+    public void whenSaveEntitiesWithManyToManyAssociation_thenSuccess_2() {
+        Author author = new Author("Erich Gamma");
+        author.addBook(new Book("Design Patterns: Elements of Reusable Object-Oriented Software"));
+        author.addBook(new Book("Introduction to Object Orient Design in C"));
+        Session session = sessionFactory.openSession();
+        session.beginTransaction();
+        session.save(author);
+        session.getTransaction().commit();
+        session.close();
+    }
+
+    @AfterClass
+    public static void cleanUp() {
+        sessionFactory.close();
+    }
+}

persistence-modules/hibernate-libraries/pom.xml

@@ -77,7 +77,7 @@
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
-            <version>${slf4j.version}</version>
+            <version>${org.slf4j.version}</version>
             <scope>provided</scope>
             <optional>true</optional>
         </dependency>
@@ -174,12 +174,10 @@
         <javassist.version>3.27.0-GA</javassist.version>
         <jaxb.version>2.3.1</jaxb.version>
         <log4jdbc.version>2.0.0</log4jdbc.version>
-        <logback.version>1.2.3</logback.version>
         <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
         <maven.compiler.version>3.8.1</maven.compiler.version>
         <maven.version>3.8.1</maven.version>
         <mysql.version>8.0.19</mysql.version>
-        <slf4j.version>1.7.30</slf4j.version>
         <spring-boot.version>2.1.3.RELEASE</spring-boot.version>
     </properties>
 

persistence-modules/java-cassandra/README.md

@@ -2,3 +2,4 @@
 - [A Guide to Cassandra with Java](http://www.baeldung.com/cassandra-with-java)
 - [Intro to DataStax Java Driver for Apache Cassandra](https://www.baeldung.com/cassandra-datastax-java-driver)
 - [CQL Data Types](https://www.baeldung.com/cassandra-data-types)
+- [Cassandra Frozen Keyword](https://www.baeldung.com/cassandra-frozen-keyword)

persistence-modules/java-cassandra/src/main/resources/frozen-keyword.cql

@@ -0,0 +1,57 @@
+CREATE KEYSPACE mykeyspace WITH replication = {'class':'SimpleStrategy', 'replication_factor' : 1};
+
+USE mykeyspace;
+
+CREATE TABLE mykeyspace.users
+(
+    id         uuid PRIMARY KEY,
+    ip_numbers frozen<set<inet>>,
+    addresses  frozen<map<text, tuple<text>>>,
+    emails     frozen<list<varchar>>,
+);
+
+INSERT INTO mykeyspace.users (id, ip_numbers)
+VALUES (6ab09bec-e68e-48d9-a5f8-97e6fb4c9b47,
+        { '10.10.11.1', '10.10.10.1', '10.10.12.1'});
+
+UPDATE mykeyspace.users
+SET ip_numbers = ip_numbers + {'10.10.14.1'}
+WHERE id = 6ab09bec-e68e-48d9-a5f8-97e6fb4c9b47;
+
+UPDATE mykeyspace.users
+SET ip_numbers = {'11.10.11.1', '11.10.10.1', '11.10.12.1'}
+WHERE id = 6ab09bec-e68e-48d9-a5f8-97e6fb4c9b47;
+
+SELECT ip_numbers
+FROM mykeyspace.users;
+
+CREATE TABLE mykeyspace.users_score
+(
+    id    uuid PRIMARY KEY,
+    score set<frozen<set<int>>>
+);
+
+CREATE TYPE mykeyspace.address (
+    city text,
+    street text,
+    streetNo int,
+    zipcode text
+    );
+
+CREATE TABLE mykeyspace.building
+(
+    id      uuid PRIMARY KEY,
+    address frozen<address>
+);
+
+INSERT INTO mykeyspace.building (id, address)
+VALUES (6ab09bec-e68e-48d9-a5f8-97e6fb4c9b48,
+        {city: 'City', street: 'Street', streetNo: 2,zipcode: '02-212'});
+
+UPDATE mykeyspace.building
+SET address.city = 'City2'
+WHERE id = 6ab09bec-e68e-48d9-a5f8-97e6fb4c9b48;
+
+UPDATE mykeyspace.building
+SET address = {city : 'City2', street : 'Street2'}
+WHERE id = 6ab09bec-e68e-48d9-a5f8-97e6fb4c9b48;

persistence-modules/java-jpa-3/README.md

@@ -14,3 +14,4 @@ This module contains articles about the Java Persistence API (JPA) in Java.
 - [How to Return Multiple Entities In JPA Query](https://www.baeldung.com/jpa-return-multiple-entities)
 - [Defining Unique Constraints in JPA](https://www.baeldung.com/jpa-unique-constraints)
 - [How to Check Field Existence in MongoDB?](https://www.baeldung.com/mongodb-check-field-exists)
+- [Connecting to a Specific Schema in JDBC](https://www.baeldung.com/jdbc-connect-to-schema)

persistence-modules/java-jpa-3/pom.xml

@@ -69,9 +69,15 @@
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>${junit.version}</version>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>1.16.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/postgresql_schema/Product.java

@@ -0,0 +1,30 @@
+package com.baeldung.jpa.postgresql_schema;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "product", schema = "store")
+public class Product {
+
+    @Id
+    private int id;
+    private String name;
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml

@@ -149,4 +149,15 @@
             <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/>
         </properties>
     </persistence-unit>
+    <persistence-unit name="postgresql_schema_unit">
+        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+        <class>com.baeldung.jpa.postgresql_schema.Product</class>
+        <exclude-unlisted-classes>true</exclude-unlisted-classes>
+        <properties>
+            <property name="hibernate.connection.driver" value="org.postgresql.Driver"/>
+            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL10Dialect"/>
+            <property name="hibernate.format_sql" value="true"/>
+            <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/>
+        </properties>
+    </persistence-unit>
 </persistence>

persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/postgresql_schema/PostgresqlSchemaLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.jpa.postgresql_schema;
+
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.postgresql.ds.PGSimpleDataSource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class PostgresqlSchemaLiveTest {
+    //This tests require running Docker application with working internet connection to fetch
+    //Postgres image if the image is not available locally.
+
+    @ClassRule
+    public static PostgresqlTestContainer container = PostgresqlTestContainer.getInstance();
+
+
+    @BeforeClass
+    public static void setup() throws Exception {
+        Properties properties = new Properties();
+        properties.setProperty("user", container.getUsername());
+        properties.setProperty("password", container.getPassword());
+        Connection connection = DriverManager.getConnection(container.getJdbcUrl(), properties);
+        connection.createStatement().execute("CREATE SCHEMA store");
+        connection.createStatement().execute("CREATE TABLE store.product(id SERIAL PRIMARY KEY, name VARCHAR(20))");
+        connection.createStatement().execute("INSERT INTO store.product VALUES(1, 'test product')");
+    }
+
+    @Test
+    public void settingUpSchemaUsingJdbcURL() throws Exception {
+        Properties properties = new Properties();
+        properties.setProperty("user", container.getUsername());
+        properties.setProperty("password", container.getPassword());
+        Connection connection = DriverManager.getConnection(container.getJdbcUrl().concat("&currentSchema=store"), properties);
+
+        ResultSet resultSet = connection.createStatement().executeQuery("SELECT * FROM product");
+        resultSet.next();
+
+        assertThat(resultSet.getInt(1), equalTo(1));
+        assertThat(resultSet.getString(2), equalTo("test product"));
+    }
+
+    @Test
+    public void settingUpSchemaUsingPGSimpleDataSource() throws Exception {
+        int port = Integer.parseInt(container.getJdbcUrl().substring(container.getJdbcUrl().lastIndexOf(":") + 1, container.getJdbcUrl().lastIndexOf("/")));
+        PGSimpleDataSource ds = new PGSimpleDataSource();
+        ds.setServerNames(new String[]{container.getHost()});
+        ds.setPortNumbers(new int[]{port});
+        ds.setUser(container.getUsername());
+        ds.setPassword(container.getPassword());
+        ds.setDatabaseName("test");
+        ds.setCurrentSchema("store");
+
+        ResultSet resultSet = ds.getConnection().createStatement().executeQuery("SELECT * FROM product");
+        resultSet.next();
+
+        assertThat(resultSet.getInt(1), equalTo(1));
+        assertThat(resultSet.getString(2), equalTo("test product"));
+    }
+
+    @Test
+    public void settingUpSchemaUsingTableAnnotation() {
+        Map<String, String> props = new HashMap<>();
+        props.put("hibernate.connection.url", container.getJdbcUrl());
+        props.put("hibernate.connection.user", container.getUsername());
+        props.put("hibernate.connection.password", container.getPassword());
+        EntityManagerFactory emf = Persistence.createEntityManagerFactory("postgresql_schema_unit", props);
+        EntityManager entityManager = emf.createEntityManager();
+
+        Product product = entityManager.find(Product.class, 1);
+
+        assertThat(product.getName(), equalTo("test product"));
+    }
+}

persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/postgresql_schema/PostgresqlTestContainer.java

@@ -0,0 +1,22 @@
+package com.baeldung.jpa.postgresql_schema;
+
+import org.testcontainers.containers.PostgreSQLContainer;
+
+public class PostgresqlTestContainer  extends PostgreSQLContainer<PostgresqlTestContainer> {
+
+    private static final String IMAGE_VERSION = "postgres";
+
+    private static PostgresqlTestContainer container;
+
+
+    private PostgresqlTestContainer() {
+        super(IMAGE_VERSION);
+    }
+
+    public static PostgresqlTestContainer getInstance() {
+        if (container == null) {
+            container = new PostgresqlTestContainer();
+        }
+        return container;
+    }
+}

persistence-modules/java-mongodb/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
-    xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>java-mongodb</artifactId>
     <version>1.0-SNAPSHOT</version>

persistence-modules/pom.xml

@@ -17,6 +17,7 @@
         <module>activejdbc</module>
         <module>apache-bookkeeper</module><!-- BAEL-2322 -->
         <module>apache-cayenne</module>
+        <module>apache-derby</module>
         <module>core-java-persistence</module>
         <module>core-java-persistence-2</module>
         <module>deltaspike</module>
@@ -101,8 +102,6 @@
 
         <!-- testing -->
         <maven-surefire-plugin.version>2.22.2</maven-surefire-plugin.version>
-        <junit-jupiter.version>5.6.2</junit-jupiter.version>
-        <junit.version>4.13</junit.version>
     </properties>
 
 </project>

persistence-modules/redis/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
-<project
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
-    xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>redis</artifactId>
     <version>0.1-SNAPSHOT</version>

persistence-modules/redis/src/test/java/com/baeldung/spring/redis/configuration/controller/BooksControllerUnitTest.java

@@ -1,21 +1,18 @@
 package com.baeldung.spring.redis.configuration.controller;
 
+import com.baeldung.spring.redis.configuration.entity.Book;
+import com.baeldung.spring.redis.configuration.repository.BooksRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.mockito.Mockito.when;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.InjectMocks;
-import org.mockito.Mock;
-import org.mockito.Spy;
-import org.mockito.junit.MockitoJUnitRunner;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-import com.baeldung.spring.redis.configuration.entity.Book;
-import com.baeldung.spring.redis.configuration.repository.BooksRepository;
-
 @RunWith(MockitoJUnitRunner.class)
 public class BooksControllerUnitTest {
 
@@ -44,8 +41,6 @@ public class BooksControllerUnitTest {
 
     @Test
     public void whenFindOneNotFound_thenReturnsNull() {
-        Book book = new Book(BOOK_ID, BOOK_NAME);
-        when(booksRepository.findById(BOOK_ID)).thenReturn(book);
         assertNull(booksController.findOne(OTHER_BOOK_ID));
     }